Coin testing device



Jan. 27,- 1942. P. STARKEY- I 2,271,104

' COIN TESTING DEVICE Filed May 4, 1939 2 Sheets-Sheet 1 //7 ran tor.-Lewz's P Starkey Attorney Jan. 27, 1942.

i L. P. STARKEY COIN TESTING- DEVICE 2 Sheets-Sheet 2 Filed May 4, 1959Patented Jan. 27, 1942 UNITED STATES PATENT oFn e com TESTING DEVICELewis P. Starkey, Larimer County, 0010. Application May 4, 1939, SerialNo. 271,775

4 Claims. (or. 1941-100) This invention relates to improvements in meansand methods for separating silver coins from slugs or tokens made fromother metal.

It is the object of this invention to produce a simple and effectivemeans for separating silver coins from coins of other metal by thecombined action of gravity and electrodynamic forces produced byvariable magnetic fluxes.

It is well known that when disks of metal, for example, silver coins orslugs or tokens made of metal or metallic compositions are moved throughan alternating or pulsating electromagnetic field, there is developedwithin the metal what is termed eddy currents which vary in strengthsubstantially in accordance with the electrical properties of the metal.These eddy currents and the electromagnetic field that produces them,react on each other in an electrodynamic manner to retard and evenprevent the passage of the coin through the field. Coins or disks havingW resistance are retarded to a greater extent than those of equal sizehaving higher electrical resistivity. Coins or disks having equaldiameters are retarded directly in proportion to their thick-' V ness,providing they are made from the same metal, and coins or disks of equaldiameter and equal thickness are retraded directly in proportion totheir conductivity. It has also been found that other things beingequal, coins or disks of large diameter are retarded to a greater extentthan similar coins or disks of smaller diameter, because they take alonger time to pass through the magnetic field.

Circular disks or coins that are permitted to roll down an inclineplane, possess at the beginning a potential energy which is convertedinto kinetic energy of motion when the coin starts rolling and since thekinetic energy varies with the square of the velocity and is equal tothe square of the velocity multiplies by one-half of the mass, itfollows that coins of the same size and material in rolling down anincline plane a given distance will attain a velocity which depends onthe extent of the inclination as well as on the specific gravity of thematerial. If coins through the magnetic flux, while an aluminum orcopper coin of the same size will be stopped by the interaction of themagnetic flux and the magnetic currents. The method employed forseparating coins in accordance with this invention is to allow them toroll downwardly along an-inclined track with one side in contact with aAn alternatingplane inclined to the vertical. current magnet ispositioned on the under side of the inclined plane and produces analternating magnetic field through which the coins: must pass, on theirway down the track. The inclination of the track, the strength of thefield and the inclinations of the non-magnetic plane are adjusted sothat a silver coin will barely pass, while a copper or aluminum coinwill be unable to pass through the flux and will remain stationary untilthe magnet is deenergized. After the silver'coin has passed through theflux or through the center of the magnetic field, the repulsive forcesproduced will cause the silver coin to run off of the track and *dropinto a coin receptacle. A copper or aluminum'coin on the other hand willbe stopped by the flux as above stated, and when released, will rollalong the track into a receptacle provided for rejected coins.

Having thus briefly described the invention, the apparatus employed willnow be described in de- 7 tail and for this purpose reference will behad to the accompanying drawings in which:

Figure 1 is a front elevation of the apparatus employed in the abovedescribed method;

Figure 2 is a side elevation looking in the direction of arrow 2, inFigure 1;

Figure 6 is a side view similar to that shown in Figure 2, but drawn totwice the scale, parts being broken away to better show theconstruction;

Figure 7 is a section taken on line 1-'!, Figure 6; and

Figure 8 is a diagrammatic view showing the circuit connections.

The apparatus which will now be described is intended primarily for usewith coin controlled gasoline dispensing devices, but may be used forany other purpose where a coin control vending device is desired. Theapparatus consists of a plate I 0, which may be made of iron, or anyother edge formed by two inclined sides I I and I2. The bottom of theplate has an opening I3 for the reception of a pivot pin and the top hasanother opening I4 for the reception of a clamping bolt by means ofwhich its position can be adjusted along a curved slot I5 in asupporting frame. The object of this adjustment will appear as thedescription proceeds.

In the drawings an apparatus has been illustrated that has threeseparate coin testing devices, one designed for silver dollars, theother for half dollars and the third for quarters. All of the devicesare constructed in the same manner and dilTer only to the extentnecessary to test coins of different sizes and therefore a descriptionof one of these devices is sufiicient for all of them. Attached to therear surface of plate I0 are three plates I6 which are preferably formedfrom copper or brass, but may be made from any nonmagnetic material,including such material as hard rubber or Bakelite. In the embodimentillustrated, however, plates I6 are made from copper and have flangesI'I that are attached-to the plate II) by rivets or other suitablemeans.

Referring now more particularly to Figures 6 and '7 where the parts areshown to a larger scale, it will be seen that the plates I6 are eachprovided'with a downwardly extending portion l8 to which attention willbe directed as the description proceeds. A rectangular bar I9 which maybe made from iron, steel or any other metal or composition is pivotallyattached to plates I6 by means of a screw 29 which forms the pivot.Plate I6 is provided with an elongated opening 2I and a screw 22 passesthrough the inclined track bar I9 and serves to clamp it in adjustedposition. By loosening the screw 22, the bar I9 can be tilted about itspivot so as to incline it to any extent desired. Plate I0 is providedwith three slots which have been designated by letters a, b and 0, slota being of the proper size to receive a dollar, slot 1) the proper sizeto receive a half dollar and slot c of the proper size to receive aquarter. In Figures 6 and '7 the plate I6 adjacent the dollar slot hasbeen illustrated and the bottom of this slot has been designated byreference numeral 23.

It will be observed from Figure 7 that plate I6 is inclined with respectto the vertical and that the track member I9 is positioned on the upperside of the inclined plate. The inclination of plate I6 corresponds withthe inclination of the slot 0. shown in Figure l. The purpose for whichplates I6 are inclined is to keep the coins from rolling off from thetrack until they are subjected to the diverting force produced when thecoins pass through the magnetic flux. When a dollar, which has beendesignated byreference numeral 24, is inserted through the slot, it willbe deposited on the upper end of track bar I9 and will roll downwardlyalong the same due to the action of gravity. A spacing bar 25 is securedto plate I6 near its top and held in place by screws 26 and 21. A guideplate 29 is positioned on the outside of the track bar I9 and the spacer25 and is secured to the latter by means of a screw 29. The front edgeof the guide plate is bent at right angles so as to form a flange 30that is secured to the plate In by rivets or other suitable means, suchas spotwelding. The downwardly extending part I8 forms one side of acoin chute whose other side has been designated by reference numeral 3!.The sides I8 and .3I areconnected at their. edges by parts '32 vided forrejected coins.

and 33. If a coin or slug of the size of a dollar is inserted throughthe dollar slot, it will roll downwardly along the track and bedeposited in a receptacle provided for the purpose which has not beenshown. In order to effect a separation of spurious coins or slugs madefrom other metal than silver, but as of the same size as a silverdollar, an electromagnet is provided and secured to the under surface ofthe plate I6 in the manner shown in Figure 7. Reference numeral 34designates the core of the electromagnet which must be laminated inorder to prevent excessive heating. The solenoid or magnetizing coil hasbeen designated by reference numeral 35 and these parts are secured tothe plate I6 by means of a yoke 36 made from soft iron. In the formillustrated, yoke 36 is a soft, fiat, steel bar bent at right angles atpoints 37 and 38. Bolt 29 secures the end 38 of yoke member 36 inposition against plate I6, while bolt 20, which serves as a pivot forthe track member I9, passes through the end portion 39 of the magneticyoke. The guide plate 28 may be made from magnetic material, such assoft iron, in which case it forms part of the magnetic circuit andprovides a return path for the flux which divides, part returning to theend member 38 and the other part returning to the end member 39 of yoke36. If guide plate 28 is made of nonmagnetic material, the flux willpass from the end of core 34 to the yoke member 36 through the air.

We will now assume that coil 35 is energized by an alternating currentand that therefore an alternating magnetic field is produced throughwhich the coin must pass while rolling down the inclined track. As soonas the coin enters the magnetic field, the rate of change of magneticlines passing through the same sets up eddy currents in the metal andthese interact with the flux to produce a force tending to stop the coinand prevent its further downward movement. If

the inclination of the track, the strength of the magnetic flux and theinclination of plate I6 are so selected that a silver coin can barelypass through the magnetic field, it will continue its movement until'itscenter has passed the center of the magnetic core, whereupon the forceswill now tend to move it downwardly and at the same time outwardly withthe result that the coin leaves the track and drops into the chuteformed between sides I8 and 3|, the center of the coin following thedotted line 40. If, instead of inserting a silver dollar, a slug of thesame size, but made of aluminum is inserted, the eddy currents set uptherein will be sufficient to produce a retarding force that will stopit entirely and hold it until the magnet has been deenergized, whereuponit will be released and rolled downwardly along the track and into acompartment (not shown) provided for its reception. A copper slug willlikewise be stopped by the forces produced by interaction of the eddycurrents and the flux and when the magnet is deenergized, it will alsoroll down into the compartment pro- If an iron slug is inserted it willbe held by the magnet until the latter is deenergized and will roll downthe track in a like manner as the other slugs. If the slug is made ofmaterial having a very high resistance compared to silver, the eddycurrents set up therein will be weak and the forces produced will not besufiicient to stop the slug which will therefore continue its movement,but it will not roll off the track because the repulsive forcesdevelopedwill not be sufilcient to cause it to do other receptacle (notshown) and will travel with their centers along line 4|.

In order to prevent the insertion of coins or slugs before the magnetshave been energized, a slide 42 is provided at the back of plate It, andthis slide extends transversely of openings a, b and c. This slide isprovided with one or more stops '43 that limit its movement in onedirection and a spring 44 that tends to move it towards the right whenviewed as in Figure 5. Stops 43 have been shown in Figure 5 asprojections extending from the edges of plate 42, two such stops havingbeen shown one of which has been designated by numeral 43. The stopsengage the wall of the opening on plate It. From Figure 1, it will beseen that plate 42 is ,provided with notches 45 that are normally out ofregister with the slots a, b and 0, but can be brought into register ifthe slide is moved towards the right. One end of slide 42 is bent atright angles so as to form a lateral projection 46 that extends over thecorresponding electromagnet and therefore when the electromagnets areenergized, slide 42 will be moved towards the left when viewed as inFigure 3 and will bring the notches 45 into register with openings a, band c, whereupon coins can be inserted. This arrangement guards againstany one inserting a coin at times when the electric circuit is dead, forif this occurred, the coin would be directed to the reject receptacle(not shown) and could not be retrieved unless the latter receptacle isso arranged that access can be had to it from the outside.

In the actual construction, the device that has just been described issecured to a housing 41 which has been indicated by dotted lines inFigure 1. A door 48 is attached at one corner to a shaft 49 that servesas a pivot and when this door is in the position indicated in Figure 1,access cannot be had to the coin slots and before any coins can beinserted, the door must be turned through an angle of substantiallyninety degrees to a position like that shown in Figure 8. Attached toshaft 49 is a mercury switch 50. When the door is in the position shownin Figure 1, the circuit through the switch is open, but when thedoorhas been moved into position to permit access to the coin slot, thecircuit. through the mercury switch is closed. The interconnection ofthe door 48 and the mercury switch assures that magnets 35 are energizedwhen the machine is in position to receive coins and that the magnetsare deenergized when the door is closed. In Figure 8, reference numeral5| indicates an alternating current generator or source and this isconnected by means of a conductor 52 with one terminal of the mercuryswitch. A conductor 53 extends from the other terminal and to thisconductor one end of each magnetic coil is connected by means of aconductor 54. The other ends of the magnetic coils are connected bymeans of conductors 55 with conductor 56 that extends to the otherterminal of the generator.

is open, the electromagnets will be connected. in parallel across thealternating current supply circuit. If the vending machine is soconstructed that an electrical circuit must berclosed by the coins,suitable switches must be provided for this purpose. In Figure 5 asimplenormally open switch comprising contacts 51 and 58 is shown assupported from the bottom of the chutes through which the coins pass,and'when the coinpasses between these ;contacts,'it closes a circuit.One of ,these contacts is connectedby meansof a conductor, 59; withconductor 53. and the other by means of a conductor 60 with conductor.56. When the circuit is closed through v.either 1 one of the threeswitches, current is caused to flow through some electromagnetic switch6 I that controls the operation. v

The above is merely intended as illustrative of means for effecting anoperation whenever acoin has been deposited in the machine, but other.and different mechanisms for this purpose may. be employed, as theinvention is directed to other features and can be used in connectionwith other operating means.

Having described the invention what is claimed as new is: l

l. A device for separating round silver coins from similarly shapedcoins of different material comprising a vertical plate having a slot ofthe proper size to permit a coin to be passed through it, a plate ofnonmagnetic material attached to and extending perpendicularly from thefirst mentioned plate in parallel relation to and adjacent the slot, atrack secured to the upper surface of the inclined plate in position toreceive and support a coin inserted through the slot, an electromagnetsecured to the under surface of the inclined plate with its corepositioned adjacent the path of the coin, a door pivoted to the firstplate for movement into and out of slot closing position, a switch inseries with the electromagnet, and means interconnecting the door andthe switch for closing the latter when the door is in slot uncoveringposition and for opening the switch when the door is returned to slotcovering position.

2. A device for separating round silver coins I from similarly shapedcoins of different material comprising a vertical plate having a slot ofthe proper size to permit a coin to be passed through it, a plate ofnonmagnetic material attached to and extending perpendicularly from thefirst mentioned plate in parallel relation to and adjacent the slot, theslot and the last named plate being vertically inclined, a track securedto the upper surface of the inclined plate in position to receive andsupport a coin inserted through the slot, an electromagnet secured tothe under surface of the inclined plate wtih its core positionedadjacent the path of the coin, a bar mounted for longitudinalreciprocating movement along the rear surface Oflthe plate having theslot, the bar having an opening which registers with the slot in oneposition of the bar, spring means for urging the bar in one direction,means comprising cooperating stops for limiting the movement of the barin response to the action of the spring, the bar having a portionthereof positioned within the range of the attraction of the magnetwhereby when the electromagnet is energized the bar will be movedagainst the action of the spring to a position in which the opening inthe bar registers with the slot whereby coins may be introduced throughthe slot only when the electromagnet is energized.

'3. In an electromagnetic device for testing coins and separatingjsilvercoins from similarly shaped coins of diflerent material, a substantiallyvertical plate having an opening for the insertion of coins, a testingmechanism positioned to receive coins that have passed through theopening, said device comprising means for constraining the coins to movein a predetermined path and an alternating current electromagnetpositioned adjacent the path whereby the coins must pass through thealternating flux field, a door movably associated with the verticalplate and movable into and out of slot closing position, an electricswitch in series with the electromagnet, and means for interconnectingthe switch and the door to close the switch when the door is moved toslot opening position and to open the switch when the door is moved toslot closing position.

4. In an electromagnetic device for testing and separating round silvercoins from similarly shaped coins of different material, a substantiallyverticalplate having an opening for the insertion of a coin, a cointesting device positioned to receive a coin that is passed through theopening, said testing device comprising an alternating currentelectromagnet, a bar mounted for longitudinal reciprocating movementalong the rear surface of the vertical plate, the bar having an openingpositioned to register with the opening in the vertical plate when thebar is in one position, a spring means associated with the bar and thetesting device for normally holding it in position to close the openingin the vertical plate, the her having a portion thereof positionedwithin the range of attraction of the electromagnet when the bar is inopening closing position, the attraction of the magnet serving to movethe bar into opening uncovering position when the magnet is energized,whereby coins can be inserted only when the magnet is energized. LEWISP. STARKEY.

